Analysis of fecal microbiome and metabolome changes in goats with pregnant toxemia.

BACKGROUND: Pregnancy toxemia is a common disease, which occurs in older does that are pregnant with multiple lambs in the third trimester. Most of the sick goats die within a few days, which can seriously impact the economic benefits of goat breeding enterprises. The disease is believed to be caused by malnutrition, stress, and other factors, that lead to the disorder of lipid metabolism, resulting in increased ketone content, ketosis, ketonuria, and neurological symptoms. However, the changes in gut microbes and their metabolism in this disease are still unclear. The objective of this experiment was to evaluate the effect of toxemia of pregnancy on the fecal microbiome and metabolomics of does. RESULTS: Eight pregnant does suspected of having toxemia of pregnancy (PT group) and eight healthy does during the same pregnancy (NC group) were selected. Clinical symptoms and pathological changes at necropsy were observed, and liver tissue samples were collected for pathological sections. Jugular venous blood was collected before morning feeding to detect biochemical indexes. Autopsy revealed that the liver of the pregnancy toxemia goat was enlarged and earthy yellow, and the biochemical results showed that the serum levels of aspartate aminotransferase (AST) and ß-hydroxybutyric acid (B-HB) in the PT group were significantly increased, while calcium (Ca) levels were significantly reduced. Sections showed extensive vacuoles in liver tissue sections. The microbiome analysis found that the richness and diversity of the PT microbiota were significantly reduced. Metabolomic analysis showed that 125 differential metabolites were screened in positive ion mode and enriched in 12 metabolic pathways. In negative ion mode, 100 differential metabolites were screened and enriched in 7 metabolic pathways. CONCLUSIONS: Evidence has shown that the occurrence of pregnancy toxemia is related to gut microbiota, and further studies are needed to investigate its pathogenesis and provide research basis for future preventive measures of this disease.

Pollution, Ecological Risk and Source Identification of Heavy Metals in Sediments from the Huafei River in the Eastern Suburbs of Kaifeng, China.

Rivers in urban environments are significant components of their ecosystems but remain under threat of pollution from unchecked discharges of industrial sewage and domestic wastewater. Such river pollution, particularly over the longer term involving heavy metals, is an issue of worldwide concern regarding risks to the ecological environment and human health. In this study, we investigate the long-term pollution characteristics of the Huafei River, an important urban river in Kaifeng, China. River sedimentary samples were analyzed, assessing the degree and ecological risk of heavy metal pollution using the geo-accumulation index and potential ecological risk index methods, whilst Pearson's correlation, principal component and cluster analyses were used to identify the sources of pollution. The results show that heavy metal concentrations are significantly higher than their corresponding fluvo-aquic soil background values in China, and the geo-accumulation indexes indicate that of the eight heavy metals identified, Hg is most prevalent, followed in sequence by Cd > Zn > Cu > Pb > Ni > As > Cr. The potential ecological risk index of the Huafei River is very high, with the potential ecological risk intensity highest in the midstream and downstream sections, where it is recommended that pollution control is carried out, especially concerning Hg and Cd. Long-term sequence analysis indicates that Cu and Pb dropped sharply from 1998 to 2017, but rebounded in 2019, and that Zn shows a continuous decreasing trend. Four main sources for the heavy metal contaminants were identified: Cr, Cu, Ni, Pb, Zn and Hg derived mainly from industrial activities, traffic sources and natural sources; Cd originated mainly from industrial and agricultural activities; whilst As was mainly associated with industrial activities. Thus, special attention should be paid to Hg and Cd, and measures must be taken to prevent further anthropogenic influence on heavy metal pollution.

Assessing the influence of immobilization remediation of heavy metal contaminated farmland on the physical properties of soil.

The potential for negative effects of heavy metal remediation on the ecological environment of soil is an issue of widespread concern. As a basic index of soil moisture and fertility retention capacity, the response of the physical properties of soil to immobilization remediation is therefore extremely important and is the main focus of this study on remediated farmland in the mining area of Tangshi village, Henan province, China. Accordingly, topsoil samples and ring knife samples were collected from five separate farmland plots, four of which had been remediated with the respective soil amendments of 1) nano silica; 2) silicate, phosphate and clay minerals; 3) biochar and organic fertilizer; and 4) biochar and phosphate; whilst for experimental control purposes the 5th plot had no remediation measures. The physical properties of particle composition, bulk density, porosity and aggregate were subsequently determined. The results show that nano silica tends to refine the soil, mainly by significantly reducing the content of sand and increasing the content of silt and clay, but did not change the soil texture type. Furthermore, nano silica can promote the formation of soil macro-aggregates and reduce the content of micro-aggregates. However, the other three amendment compositions show no significant effect on soil particle composition and aggregate content. On the whole, the amendments of the four remediation plots can significantly reduce soil bulk density and increase porosity, thus facilitating soil changes that are more beneficial for crop growth. The results, therefore, go some way into alleviating the concerns surrounding heavy metal remediation and damage to the ecological environment of soil.